Lesson 8: Practice Problems

Problem 1

Different stores across the country sell a book for different prices. The table shows the price of the book in dollars and the number of books sold at that price.

price in dollars	number sold
$11.25$	$53$
$10.50$	$60$
$12.10$	$30$
$8.45$	$81$
$9.25$	$70$
$9.75$	$80$
$7.25$	$120$
$12$	$37$
$9.99$	$130$
$7.99$	$100$
$8.75$	$90$

Draw a scatter plot of this data. Label the axes.
Are there any outliers? Explain your reasoning.
If there is a relationship between the variables, explain what it is.
Remove any outliers, and draw a line that you think is a good fit for the data.

Problem 2 From Unit 6 Lesson 7

Here is a scatter plot:

A scatter plot of age (weeks) vs weight (pounds). The data starts at (0,0), rises sharply and then levels off.

Select all the following that describe the association in the scatter plot:

Linear association
Non-linear association
Positive association
Negative association
No association

Problem 3 From Unit 6 Lesson 6

Using the data in the scatter plot, what can you tell about the slope of a good model?

A scatter plot with mostly a negative correlation.

The slope is positive.
The slope is zero.
The slope is negative.
There is no association.